Machine tool



Nov. 24,r 1942. B. R. GRANBl-:RG ETAI.

MACHINE TOOL Filed May 20, 1940 Nov'. 24, 1942.

B. R. GRANBERG ETAL MACHINE TooL Filed May 2o, 1940 -3 Sheets-Sheet 2 Nov. 24, 1942. B. R. GRANBERG ETAL 2,302,854

MACHINE TOOL Filed May 20, 1940 3 Sheets-Sheet 3 INVENTOR. Gr er BY 65E/26@ rz'cozig ceu ATTORNEY.

Patented Nov. 24, 1942 M'ACHINE TOOL Bengt R. Granberg and Alfred G. Ericson, Rockford, Ill., assignors to Sundstrand Machine Tool Co., Rockford, Ill., a corporation of. Il-

'lillois Application May 20, 1940, Serial No. 336,118

19. Claims.

The invention relates generally to a machine tool, and more particularly to a feed mechanism for the tool carriage and cross `slide thereof;

The' general object of the invention is to provide a new and improved feed mechanism for the carriage and cross slide of a machine tool capable of producing diferent and improved movements of the carriage and the cross slide.

A more particular object of the invention is to perfect a new and improved feed mechanism for the carriage and cross slide of a machine tool in which the cross slide may be moved independently of the carriage.

Another object is to provide in a machine tool having a carriage, a cross slide and power means for driving the same, a feed mechanism for the carriage and a cross slide which includes a feed bar driven from the power means and having separate driving connections with the carriage and cross slide respectively.

It is also an object of the invention to provide in a machine tool, having `a carriage, a cross slide and power means with separate driving connections for the carriage and cross slide respectively, means for adjusting said connections for variously timing the actuation of the carriage and cross slide with respect to each other for obtaining different cycles of movement thereof.

And it is also an'object to provide in a machine tool, having a carriage, a feed mechanism for the carriage including a driving member and a rotatively mounted member on the carriage functioning as a connection between the driving member and the carriage but controllable for rendering the connection ineffective, together with controlling means governing the connection in a manner to permit slowing down of the carriage before it stops.

l Other objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

Fig. 1 is a fragmentary plan view of a ma- Fig. 5 is a fragmentary front elevation of a machine tool showing a modified form of carriage feed with a slow-down mechanism.

Fig. 6 is a detail section taken as indicated at line 6-6 on Fig, 5.

While the invention is susceptible of various modifications and alternative constructions, it is shown in the drawings and will be described hereinafter in a preferred'embodiment and one modification, but 4it is not intended that the invention is to be limited thereby to the specic embodiments disclosed, but it is intended to cover all modiiications and alternative constructions falling Within the spiritand scope of the appended claims.

For purposes of disclosure the invention is here shown embodiedl in a lathe of the same general characteras that illustrated in the co-pending application of Bengt R. Granberg and Alfred G.

' Ericson, Serial No. 228,522,2iled September 6,

1938. The lathe comprises generally abed Ii) with a head stock Il at one end journalingV a spindle I2. A horizontal guideway I3, formed on the bed' I0 or securedthereto, slidably supports a carriage I4' for movement longitudinally of the lathe, Vand the carriage is equipped'with a cross slide I5 supporting the tool holder I6 in which 'the cutting tool, indicated at I'I, is secured in any convenient manner. For certain classes of work the lathe is provided with a tail stock I 8 having a center I9 engaging the work-piece, such as that shown at 20 in Figs. 1 and 2. It will be understood 'that suitable power means is provided for driving the spindle I2, and that suitable connections therefrom, or independent power means, will be provided for driving the carriage and its cross slide; `and in a production machine of this character certainmovements and adjustments may be effected by the application of compressed air mechanism, but for the purpose of simplifying the drawings these power connections and mechanisms are omitted, since they may be conventional, and detailed ldescription of them is unnecessary for an understanding of the present invention.

The carriage I4 includes a vertical front or apron portion 2l and a horizontally extending table portion 22 on which the slide I5v is carried. These parts include bearing surfaces` whichv t slida-bly against the vertical and horizontal faces of the gui-dewayY I3and are maintained in proper relation thereto by gibs, indicated at 23 and 24 in Fig. 3. They travel of the cross slide I5 isconrolled by the engagement of a cam follower pin 25 which bears normally against a cam bar 25 extending through a suitable guideway 2l formed in the table portion 22 of the carriage; and during operation of the tool Il the pin 25 is held in Contact with the cam face of the bar 26 by air pressure applied in an air cylinder 28, having a piston rod 29 anchored in the apron 2| of the carriage while the head 36 of the cylinder is secured directly to the cross slide I5, as seen in Fig. 3.

In its longitudinal travel on the guideway I3 the carriage I4 is driven by means of a feed bar 3| having rack teeth 32 which mesh with the teeth of a driving pinion 33 actuated from any suitable power source, not shown. Driving connection between the feed bar 3| and the carriage I4 is provided by a gear 34 rotatably journaled on the apron 2| of the carriage I4 and meshed with the teeth of a supplemental rack 35 secured rigidly to the feed bar 3|. If the gear 34 were freely rotatable, the longitudinal movement of the feed bar 3| would merely turn the gear 34 without causing any movement of the carriage, but said gear 34 also meshes with rack teeth on a vertically disposed plunger 36 guided for reciprocation in the apron of the carriage I4; and, as shown in Fig. 2, the lower end of the plunger 3| engages a horizontal surface 31a of a control cam bar 31 supported rigidly on the frame of the machine. Thus when the pinion 33 is revolved in a direction to move the feed bar 3| forwardly-that is, toward the head stock Il the tendency for the rack 35 to rotate the gear 34 and feed the plunger downwardly is checked by the engagement of the plunger with the horizontal cam surface 31a with the result that the gear 34 locks the carriage I4 to the feed bar 3| for travel therewith. In the form shown, the cam bar 31 is provided with stepped cam surfaces 31a, 31h, 31 and 31d. As the carriage moves forward the plunger 36 eventually reaches the end of the surface 31a. and the torque of the gear 34 is permitted to drive the plunger 36 downward onto the next step 31h; but during such rotation of the gear 34 the carriage I4 will stand still while the feed bar 3| continues to travel relatively to the carriage so as to rotate the gear 34 and feed the plunger 36 through the limited distance between the level of the cam surface 31a and that of the surface 31h, It will be apparent that upon encounter of the plunger 36 with the cam surface 31b further rotation of the gear 34 will become impossible, with the effect that the c-arriage I4 will again be locked to the feed bar 3| for further forward movement. With a cam bar 31 of the form illustrated the carriage I4 will be arrested again as the plunger moves from the level of the cam surface 3lb to that of 310, and once more when the plunger has traversed the surface 31 and is shifted to the surface 31d.

It will be observed that the particular workpiece 23 which is chosen for the purposes of illustration is of stepped formation, and it may be explained that the purpose of arresting the carriage I4 after each interval of forward travel, as just described, is to allow time for the tool I1 t0 withdraw from the position in which it has been cutting one sten of the work-piece 25.! to a position for cutting or nishing the next step of said piece. Such withdrawal of the tool I 1 is accomplished under control of the cam bar 26 which, in conjunction with the air cylinder 23, causes the.

necessary transverse movement of the cross slide l I5 by which the tool I1 is carried. The operation of the cam bar 26 is very similar to that of a corresponding element shown in our co-pending application Serial No. 228,522, but will 110W be briefly described.

The machine is equipped with a bracket 40 which is adjustably but fixedly secured to the bed I 0, and in which there is journaled a vertical shaft 4| having a gear 42 at its lower end, and a gear 43 at its upper end. A cylindrical rack bar 44 is slidably mounted in the bracket 40 with its teeth meshing with the gear 42, and this rack 44 is coupled to the feed bar 3| for movement therewith. Its relation to the feed bar 3| is rendered adjustable by means of a threaded rod 45, and suitable clamping nuts on said rod, as more fully described in our said cio-pending application Serial No. 228,522, but for the purposes of the present description it may be understood that the rack 44 moves as a unit with the feed bar 3|. Such movement of the rack 44 rotates the gear 42 and shaft 4I, thus transmitting rotation to the gear 43 at the upper end of said shaft and corresponding movement to the cam bar 26 which is provided with rack teeth meshing with the gear 43, as seen in Fig. l. The arrangement is such that movement of the feed bar 3| and rack bar 44 toward the head stock II produces movement of the cam bar 26 in the opposite direction; but this movement is not arrested with the arrest of the carriage I4 which occurs when the plunger 36 is shifted from one level of the control bar 31 to its next step or level. Thus, while the carriage I4 stands still, the rack bar 26 continues to move to the right, as viewed in Fig. l, so that the follower pin 25 engages one of the inclined cam -faces 0f the cam whereby the cross slide I5 is shifted inwardly or outwardly to a position ready for operation upon one yof the cylindrical surfaces of said work-piece 20, or nally, to a position clear of the work and ready for return travel of the tool carriage to its starting point.

To clarify the operation and relative movements of the carriage I4 and its cross slide I5, a single complete cycle of tool movement will be described. The operator, having placed the work-piece 20 in position between the spindle I2 and the center I9, will start the machine, the carriage being in its initial position at the .extreme right end of its range of travel as adjusted for this particular piece of work. The first movement of the feed Ibar 3| Will rotate the gear V34 in the direction for shifting the plunger 36 from its extreme upper limit downwardly into contact with the upper surface 3`|a of the control Cam bar 31, as shown in Fig. 2; then, with the plunger thus engaging the surface 31a, the carriage will travel to the left. Substantially at the commencement of this movement the air cylinder 28 will be actuated automatically to press the follower pin 25 against the surface 26| of the cam bar 26. As the air pressure holds the pin 25 to the bar 26 it follows the inclined portion 262, causing the cross slide I5 and the tool I1 to move inwardly to the first cutting position, while the carriage continues its travel toward the left, and as the pin 25 traverses the surface 263 of the cam bar 26, the tool I1 performs its first cut upon the portion a of the work-piece 2|). Just at the completion of this cut the plunger 36 leaves the surface 31ai and the forward travel of the carriage ceases while the plunger is fed toward the surface 31h of the control bar 31; but during this interval the cam bar 26 continues to move to the right, causing the pin 25 to traverse the inclined surface 264 and withdrawing the cross slide I5 and its tool to the proper position for making the next cut. When the plunger 36 contacts the step i 31b the carriage is again locked to the feed bar 3|, and its forward travel is resumed, while the tool I1 performs its cutting operation on, the part b. of the Work-piece and-the follower pin traverses thev portion 265 of bar 26. W'hen the carriage is again arrested While the plungermoves from cam face 3.1lo to the surface 31, the pin 25 traverses the inclined surface 266 and withdraws the tool. to position for its third cut, which is made upon the portion. c of the work-piece 20, with the plunger 36Y contacting the surface 31c and with the rpin 25- riding along the portion 261 of the bar 26; Finally when the plunger runs off the end of the surface 31c and moves toward 31d the pin 25fis engaged by the inclined face 268 for Withdrawing the tooll from the work to a proper position for return travelofA the carriage to its starting point, and the air cylinder then releases its pressure-on the p-in 25.

Such return travelr is accomplished by automatic reversal of the rotation of the feed pinion 33, causing the feed bar 3l to move to the right. This movement first produces reverse rotation of the gear 34, thus raising the plunger 36 to its upper limit, clear of the cam face 31a of the bar 31. Thereupon, the further movement of the feed bar 3| to the right is transmitted to the carriage by an extension rod 4.6 secured to the end of' the bar 3! and Iprovided with adjustable stop nuts 41 which engage a lug 48 on the carriage, as seen in Fig. 2. The return movement of the carriage is limited by a collar 49 carried on a rod 53 which extends from the carriage M through the bracket Ml, so that the collar d!! abuts the bracket at one limit of 'carriage movement.

At the opposite limit an adjustable stop nut on the threaded end of the rod 5i! abuts a stop sleeve 52 carried by the bracket 4l) and cushioned on a spring 53 pocketed Within the bracket Ml, as seen in Fig. 4.

It will be understood that for machining a piece of Work ofv different contour from. that shown at 2l] the control cam bar 31 must be of somewhat different proportions. and the camr bar 26 may be formed with steps and oblique sections of different dimensions. If desired, the bars 26 and 31 may be made with applied cam elements in the form of blocks screwed'in place so that these blocks may be shifted 'and adjusted to some extent for altering the eiectivecam faces. And for vaccurately relating the operation of the bar 31 to that of the bar 26 thel bar 31 is adjustably mounted by means of a threaded rod 54 secured by clamping nuts 55 in a portion 40a of the bracket 40.

Figs. 5 'and 6 illustrate a modification of the lmechanism for controlling the travel of the' carriage whenl it is desired to arrest such travel gradually'and gently at a regulated or controlled rate. Fig. 5 shows a carriage 66 and a feed bar 6| with a supplemental raekbar 62 carried thereby. The feed bar is driven from a pinion 63 and the supplemental rack 6.2 meshes with the teeth of a gear Wheel 64 which has rigid with it a .smaller gear 65 in mesh with the teeth of the Shall cause. corresponding movement of the Carriage 60, Bu, heend. ofv the earn bar 61 includes an oblique sl-ioulder 61h, and, preferably, the. plunger '66. is fitted` with a roller 68 which travels along this oblique surface. 61.b when the plungerpasses theend of the. horizontal face 61a. Thefoblique relation of, the face. 613 to the direction,N in which the plunger 66; can. travel in its guideway .69, requiresthat the. descent of the plunger; 66 inA its. guideway 69 be accompanied by a certain amount of travel of the carriage 6l) longitudir-lallyV of the bar 61.. In other words, a certain portion of the movement of the feed bar 6iv istranslated by the. gear wheels 64 and 65 into transverse movement of the plunger 66, but the..rernainingportion of the movementis utilized to produceV forward. travel ofthe carriage at a reduced rate of speed.. In this way the., travel of thecarriageyrnay be slowed down before the carriageis brought torest, so that the. cutting movement of the tool may be terminated very accurately,` or thereverse travel ofthe carriage may be initiated after the parts have been brought to rest gradually and. gently, thus avoiding unnecessary shock in the operation of the. machine. After .the plungerroller.v 68. hastraversedthe full length of ltheinclined or obliquecam face 6,1b it will move a short distancedownwardly along the vertical face 61.c at theendof the cam bar 61, and in the con st'riuctiorras shown it is contemplated that the drivepinion 63. will then be reversed. This will first cause reverse rotation of the'gears 64 and 65, resulting in transverse movemen-t of the plunger 66` upwardlyuntil. its` upper end strikes the end wall. 1l) of the guidewayl 68, thus arresting the-plunger and interlocking the carriagel With the rack 62 and feed. bar 6| to which the rack is secured. Thereafter the feed bar will draw the carriage backuntilit reaches its starting position andisarrestedby any suitablerneans similar to that employed in the structure shownv in Figs. l to 4, or by stopping vthe. drive pinion 63.

For the purpose of accurately timing the action of thefcam bar 61 andV its oblique face 61h the bar may be adjustably-carried by a threaded rod 1l engaged in a bracket 12 and'securedhat adjusted position lby means of..nuts-13. In the carriage Ell,` the bar 61r is accommodated in a fitted guide- Wafyandprovided, with an anti-friction roller 14 to insure smooth operation.

In the particular struct-ureillustrated in` Figs. 5 and 6 it- Wi-ll @be Ynoted. that the gear 64 is considerably larger than the gear 65, thus causing the plunger i-tto-be driven downwardly at a rate of speed which is appreciablysloweri than the movement of the feedv bar 6l andjits associated rack- 62 relative to the carriage Sil. This relation of thegears; addedzto-theretarding effect of the obliguecam face 611?,- may be made to reduce the speedof carriage, travel toone-fourth. vor onefifth, or-any: otherdesired fraction ofy its normal feed irl-working direction, thus vinsuring ran accuratefstop at the limit `ofthe cuttingmovement, and preparingthecarriagefor a prompt reversal. without shock. And vif it should be desirable, in .a-particulan case, to reducethe feed of the carriage.' dur-ing an.A intermediate portion of the cuttingf operation, a. depression'may be formed, as indicated in dottedoutline at 61d, in the upper face ofthe carnhar6g1., thusallowing the plunger 66 to move downwardv temporarily so as to absorb a part of the feedingnnovement derived from the feedbarSl;

Weclaim as, our: invention 1. Ina machinetoolpa carriage mounted for reciprocatory movement, a reciprocatory driving member mounted for movementI relative to said carriage, and a driving connection between said' driving member and said carriage including a toothed gear journaled for rotation on the carriage and meshing with rack teeth on said driving member, and a toothed member constantly meshing with said gear and movable thereby on the carriage in response to rotation of the gear, together with means directly controlling the movement of said toothed member and thereby controlling movement of the carriage.

2. In a machine tool, a carriage mounted for reciprocatory movement, a reciprocatory driving member mounted for movement relative to said carriage, and a driving connection between said driving member and said carriage including a toothed gear member journaled for rotation on the carriage and meshing with rack teeth on said driving member, and a toothed plunger constantly meshing with said gear member and movable thereby ,on the carriage transversely of the direction of movement of the carriage, together with means providing a control surface along which the carriage travels positioned for encounter by said plunger and extending for engagement therewith during travel of the carriage.

3. In a machine tool, a carriage mounted for reciprocatory movement,v a reciprocatory driving member mounted for movement relative to said carriage, and a driving connection between said driving member and said carriage including a toothed gear member journaled for rotation on the carriage and meshing with rack teeth on said driving member, and a -toothed plunger constantly meshing with said gear member and movable thereby on the carriage transversely of the direction of movement of the carriage, together with means providing a controlr'surface along which the carriage travels positioned for encounter by said plunger and extending for engagement therewith during travel of the carriage, the contour of said control surface including a portion parallel to the direction of travel of the carriage for holding the plunger and gear member stationary and rendering the driving connection effective, said surface also including a non-parallel portion in following which theplunger moves transversely of the direction of ,carriage travel, releasing said gear member for rotation and retarding the travel of the carriage,

4. In a machine tool, a carriage mounted for reciprocatory movement, a reciprocatory driving member mounted formovement relative'to said carriageJ and a driving connection between said driving member 'and said carriage including a toothed gear member journaled for rotation on the carriage and meshing with rackY teeth on said driving member, and a toothed plunger constantly meshing with said gear member and movable thereby on the carriage transversely of the direction of movement of the carriage, together with means providing a control surface along which the carriage travels positioned for encounter by said plunger and extending for engagement therewith during travel of the carriage, the contour of said control surface including a portion parallel to the direction'of travel of the carriage for holding the plunger and gear member stationary and rendering the driving connection effective, said surface also including a transversely extending portion parallel to the direction in which the plunger is mounted for movement on the carriage whereby movement of the driving member is transformed .into transverse fue movement of the plunger along said transverse portion of the control surface for arresting the travel of the carriage without stopping the driving member.

5. In a machine tool, a carriage mounted for reciprocatory movement, a reciprocatory driving member mounted for movement relative to said carriage, and a driving connection between said driving member and said carriage including a toothed gear member journale'd forV rotation on the carriage and meshing with rack teeth on said driving member, and a toothed plunger constantly meshing with said gear member and movable thereby on the carriage at' right angles to the direction of movement of the carriage, together with means providing a control 'surface along which the carriage travels positioned for encounter by said plunger and extending for engagement therewith during travel of the carriage. the contour of said control surface including'a portion parallel to the direction of travel of the carriage for holding the plunger and gear member stationary and rendering the driving connection eifective, said surface also including a perpendicularly extending portion whereby all movement of the driving member is transformed into rotation-of the gear member and movement of the plunger along said perpendicular portion of the control surface for arresting the travel of the carriage without stopping the driving member.

6; In a machine tool, a carriage mounted for reciprocatory movement, a reciprocatory driving member mounted formovement relative to said carriage, and a driving connection by which` movement is transmitted from said driving member to said carriage including a toothed gear member iournaled for rotation on the carriage and meshing with rack teeth on said driving member, and a holding member mounted on the carriage for movement transversely of the direction of carriage travel and operatively connected to said gear member to be so moved by rotation thereof, together rwith a control bar extending adjacent the path of travel of the carriage and having a face along which said holding member is slidable as the carriage advances, 'said face including a portion parallel 'to the direction of carriage movement whichprevents transverse movement of the holding member and rotation of the gear member, thus maintaining operative driving connection between the driving member and the carriage, and said face having also a transversely trending portion along y'which the holding member is moved by rotation of the'gear member, thus modifying the yeffectiveness of said gear member in transmitting movement from the driving member to the carriage.

7. In a machine tool, a carriage mounted for reciprocatory movement, a cross slide on the carriage, a reciprocatory driving member mounted for movement relative to said carriage, an actuating member connected for moving the cross slide transversely of the direction of carriage movement, means interconnecting said actuating member and said driving memberl for simultaneous operation, and a driving connection between said driving member and Ysaid carriage including a toothed gear member journaled for rotation on the carriage and meshing with rack teeth on said driving member, and control means arranged for holding said `gear against rotation during a predetermined travel 'of the carriage, thereby rendering the driving connection effective for causing` such travel said means then releasing said gear and thereby rendering the driving connection ineffective and arrest the carriage without stopping the movement of the driving member and the 'actuating member connected therewith.

8. In a machine tool, a carriage mounted for reciprocatory movement, a reciprocatory driving member mounted for movement relative to said carriage, and a driving connection between said driving member and said carriage including a plunger mounted on the carriage ior movement transversely of the direction of travel of the carriage, a xed guide bar extending along the path of carriage travel and engaging the plunger, and motion-transmitting means connecting the plunger with said driving member, the guide bar including a portion extending parallel to the direction of carriage movement to hold the plunger stationary on the carriage and render the driving connection eiective for fully applying movement of the driving member to the carriage, and said guide bar having also an obliquely extending portion along which the plunger is moved by the driving member acting through said transmitting means, while only a portion of the driving member movement is applied to the carriage and said carriage is thus retarded.

9. In the combination dened in claim 8, said guide bar having a terminal portion adjoining its oblique portion and extending parallel to the direction oi plunger movement, the plunger being advanced along said terminal portion by the application of the whole movement of the driving member, whereby none of said movement is applied to the carriage and said carriage comes to rest.

10. In the combination defined in claim 8, said motion-transmitting means including speed reducing gearing which causes the plunger to traverse said oblique portion of the guide bar at slow speed, thus augmenting the resultant retardation of the carriage.

1l. In a machine tool, a carriage mounted for reciprocatory movement, a reciprocatory driving member mounted for movement relative to said carriage, and a driving connection between said driving member and said carriage including a toothed gear journaled for rotation on the carriage and meshing with rack teeth on said driving member, a small gear rigid with the rst mentioned gear, and a toothed plunger meshing with said smaller gear and mounted on the carriage for movement transversely of the direction of movement of the carriage, together with means for providing a control surface positioned for encounter by said plunger and extending for engagement therewith during travel of the carriage, the contour of said control surface including a portion parallel to the direction of travel of the carriage for holding the plunger and gears stationary and rendering the driving connection eiective, said surface also including an obliquely extending portion along which the plunger is moved by the driving member acting through said gears, whereby only a portion of the driving member movement is applied to the carriage while the plunger is traversing said oblique portion of the control surface and the carriage is thus retarded. l

12. In a machine tool, a carriage mounted for reciprocatory movement, a reciprocatory driving member mounted for movement relative to said carriage, and a driving connection by which movement is transmitted by said driving member to said carriage including a toothed gear member journaled for rotation on the carriage and meshing with rackteeth on said driving member, and a holding member mounted on the carriage for movement transversely of the direction of carriage travel and operatively connected to be so moved by rotation of said gear member, togetlrer with means positively controlling such transverse movement of the holding member and thereby timing the motion transmitted to the carriage from the driving member.

13. In a machine tool, la carriage mounted for reciprocatory movement, a reciprocatory driving member mounted for movement relative to said carriage, and a driving connection between said driving member and said carriage including a toothed gear member journaled for rotation on the carriage and meshing with rack teeth on said driving member, and means for controlling said gear member comprising a cam element and a follower element, the follower element being mounted on the carriage for movement transversely of the direction oi' carri-age travel and being operatively connected to be so moved by rotation of said gear member, the cam element extending adjacent the path of carriage travel and having a face along which a cooperating face oi" the follower is sliolable as the carriage advances, said face of the cam element including a portion parallel to the direction of carriage movement which prevents transverse movement of the follower element and rotation oi' the gear member ior maintaining an eiective connection between the driving member and the carriage, said parallel portion adjoining a transversely extending portion in contact with which the follower is movable to permit rotation of the gear member, one of said contacting elements being oblique to the direction of movement oi the follower whereby during such transverse movement a portion of the driving member movement is applied to the follower and only the remainder oi such movement is applied to the carriage so that the travel of the carriage is retarded.

i4. In a machine tool, a carriage mounted for reciprocatory movement, a reciprocatory driving member mounted for movement relative to said carriage, and a driving connection between said driving member and saidcarriage including an element mounted on the carriage for movement transversely of the direction of travel of the carriage and in response to movement of the driving member, together with means extending along the path ol carriage travel engaging said element, said means having a portion extending parallel to the direction oi carriage movement to hold said element stationary on the carriage and render the driving connection effective for fully applying movement of the driving member to the carriage, and said means having also an obliquely extending portion along which the said element is moved for causing only a portion of the driving member movement to be applied to the carriage, whereby the travel of the carriage is retarded.

l5. In a machine tool, a carriage mounted for reciprocatory movement, a reciprocatory driving member mounted for movement relative to said carriage, and a driving connection between said driving member and said carriage including an element mounted on the carriage for movement transversely of the direction of travel of the carriage, motion-transmitting means connecting said element with the driving member, and a fixed guide extending along the path of carriage travel engaging said element, saidV guide having a portion extending parallel to the direction of carriage movement to hold said element stationary in the carriage and render the driving connection effective for fully applying movement of the driving member to the carriage, and said guide having also an obliquely extending portion along which the said element is moved for causing only a portion of the driving member movement to be applied to the carriage, whereby the travel of the carriage is retarded.

16. In a machine tool, a carriage mounted for reciprocatory movement, a reciprocatory driving member mounted for movement relative to said carriage, and a driving connection between said driving member and said carriage including an element mounted for movement about an axis on the carriage and transmitting movement to said carriage by direct engagement with the driving member, and a holding member operatively connected to said element and mounted for movement thereby transversely of the direction of carriage travel, together with fixed means adjacent which the carriage travels, said means controlling such transverse movement of the holding member and thereby controlling the motion transmitted to the carriage from the driving member.

17. In a machine tool, a carriage mounted for reciprooation, a reciprocatory driving member, transmitting means mounted on the carriage movable relatively thereto and in constant engagement with said driving member and fixed control means adjacent which the carriage travels operating to hold said transmitting means against relative movement on the carriage to effect travel of the carriage bdily with the driving member and subsequently permitting such relative movement of the transmitting means to effect travel of the carriage at a slower rate.

18. In a machine tool, a carriage mounted for reciprocation, a reciprocatory driving member, a transmitting member mounted on the carriage movable relatively thereto and in constant engagement with the .driving member, and means controlling the rate of relative movement of the transmitting member on the carriage and thereby controlling the proportion of the movement of the driving member which is effective to cause travel of the carriage.

19. l'n a machine tool, a carriage mounted for reciprocation, a reciprocatory driving member, transmitting means mounted on the carriage, movable relatively to said carriage and in constant engagement with the driving member, and fixed control means adjacent which the carriage travels with said transmitting means in engagement therewith, two different portions of the control means being formed to cause the relative movement of the transmitting means on the carriage at different rates respectively and to thereby efect travel of the carriage at two different rates during different portions respectively of its movement in one direction.

BENGT R. GRANBERG. ALFRED G. ERICSON. 

